Our prior application Ser. No. 09/303,839, describes a novel electrosurgical handpiece for treating tissue in a surgical procedure commonly known as minimally invasive surgery (MIS). Among the features described and claimed in the prior application is an electrosurgical handpiece that can be used in MIS and reduces the danger of excessive heat causing possible patient harm. This is achieved in one embodiment by an electrosurgical handpiece that is bipolar in operation and that is configured for use in MIS. The bipolar operation confines the electrosurgical currents to a small active region between the active ends of the bipolar electrode and thus reduces the possibility that excessive heat will be developed that can damage patient tissue. Moreover, the position of the active region can be controlled to avoid patient tissue that may be more sensitive to excessive heat. Preferably, the handpiece is provided with a dual compartment insulated elongated tube, each of the compartments serving to house one of the two wires of the bipolar electrodes. The electrode for MIS use is preferably constructed with a flexible end controllable by the surgeon so as to allow the surgeon to manipulate the end as desired during the surgical procedure. In a preferred embodiment, the flexible end is achieved by weakening at the end the housing for the electrode, and providing a pull string or wire connected to the weakened housing end and with a mechanism at the opposite end for the surgeon to pull the string or wire to flex the housing end to the desired position. This feature allows the surgeon to position the active electrode end at the optimum location for treating, say, a herniated disk to remove undesired regions and to provide controlled heat to shrink the tissue during surgery. In FIGS. 3–7 of the prior application, a suitable bipolar electrode is described, which comprises a pair of rounded electrodes with spaced flat sides separated by an insulating layer. FIGS. 8–10 illustrate a suitable unipolar electrode construction of the flexible end handpiece. FIG. 12 illustrates how such an electrode can be used for the reduction of herniated disks in a laparoscopic procedure. FIG. 19 shows a construction that combines both a bipolar and a unipolar electrode either of which can be selected by the surgeon for use with the procedure. FIG. 20 shows a scissors end that can be constructed as a bipolar electrode for certain purposes. Other constructions to provide easier flexing of the handpiece end, as well as the use of memory metals to control the position of the extended electrode are also discussed.
Our prior application Ser. No. 09/393,286, describes a modified bipolar electrode construction using the flexible end handpiece, the modified bipolar electrode having spaced prongs.
Our prior application Ser. No. 09/483,994, describes a modified bipolar electrode construction using the flexible end handpiece, the modified bipolar electrode having spaced loops.
One limitation of the handpiece constructions described in these prior applications is the relatively high fabrication costs, which deters single uses of the handpiece by the surgeon. Nowadays, surgeons prefer if feasible disposable instruments that can be discarded after one use and no longer need sterilization and sterile packaging for future uses.